CATALYTIC  OXIDATION  OF  METHANE 


BY 

FORREST  EVERETT  KENDALL 


DEGREE 

THESIS 

FOR  THE 

OF  BACHELOR  OF  SCIENCE 

IN 

CHEMISTRY 

COLLEGE 

OF  LIBERAL  ARTS  AND  SCIENCES 

UNIVERSITY  OF  ILLINOIS 


1921 


■ 


\^ZA 

K^'b 


UNIVERSITY  OF  ILLINOIS 


__.MM_.27j l 192.U. 


THIS  IS  TO  CERTIFY  THAT  THE  THESIS  PREPARED  UNDER  MY  SUPERVISION  BY 


Forrest  Everett  Kendall 


IS  APPROVED  BY  ME  AS  FULFILLING  THIS  PART  OF  THE  REQUIREMENTS  FOR  THE 


DEGREE  OF ^ _ P. L _ A?_ S_t  ry_ 


structor  in  Charge 


Approved  : 


. hCj.  fC- 


HEAD  OF  DEPARTMENT  OF  str^.. 


AY'jl^lX  .'As 
411 : c O r-’  U'-tt- 


Digitized  by  the  Internet  Archive 
in  2015 


https://archive.org/details/catalyticoxidatiOOkend 


ACKNOWLEDGMENT 


I take  this  opportunity  to  thank  Dr.  Reedy 
for  his  generous  assistance  and  advice  upon 
this  problem,  and  also  for  the  inspiration 
that  I have  derived  from  association  with  him. 


.Forrest  Everett  Kendall. 


TABLE  OF  CONTENTS 


Introduction 1 

Theoretical  and  Historical 3-8 

Experimental 8-10 

Results 10  - 12 

Conclusion 12 


Bibliography 


13 


INTRODUCTION. 


Statement  of  problem : 

The  partial  oxidation  of  methane  giving  methyl  alcohol 
and  fomaldehyde  as  products  is  a problem  the  successful 
solution  of  which  would  lead  to  important  commercial  applic 
at ion.  Large  supplies  of  methane  in  the  form  of  natural  ga 
exist  in  this  country,  and  successful  solution  of  this 
problem  would  make  this  gas  available  as  a cheap  source  of 
methyl  alcohol  and  formaldehyde,  both  of  which  are  finding 
ever  increasing  uses  in  industry.  The  greater  part  of  the 
work  dealing  with  the  batalytic  oxidation  of  methane  to 
alcohol  and  formaldehyde  is  found  in  the  patent  literature. 
The  object  of  the  work  presented  in  this  paper  was  to  in- 
vestigate some  of  the  processes  discussed  in  the  patents 
and  more  expeciaily  to  investigate  the  catalytic  effect  of 
metals  and  metallic  oxides  upon  the  oxidation  of  methane. 


-2- 


THEORETICAL  and  HISTORICAL. 

The  question  as  to  now  the  methane  is  attacked  ty 
oxygen  during  oxidation  is  one  of  the  greatest  importance  in 
this  problem.  Does  the  oxidation  proceed  by  sucessive 
hydroxylization  of  the  methane  molecule  followed  by  dehyd- 
ration or  is  the  whole  molecule  oxidized  simultaneously? 

The  mechanism  of  this  reaction  was  studied  rather  extensively 
by  Bone  and  Y/haler.^  Passing  a mixture  of  methane  and 
oxygen  rapidly  through  a bor-silicate  glass  tube  at  a temp- 
erature of  500°C  for  a period  of  ten  days  and  removing  the 
intermediate  products  of  combustion  by  a system  of  scrubbers, 
they  were  able  to  obtain  yields  of  20$  of  formaldehyde  but 
no  trace  of  methy  alcohol.  They  conclude  that  the  oxidation 
of  methane  proceeds  in  the  following  manner. 

H OH 

I I 

H-C-H  + 0=0  — * H-C-H  > H-O=0  +-  Ho0 

i i i 2 

H OH  H 

HCHO  -t  Op  -^H^O  + CO 2 
2HCE0  + On  -^HgO  + 2C0 

They  believe  the  intermediate  formation  of  CH3OE  is  extremely 
doubtful  at  this  temperature.  However  the  evidence  presented 
by  them  cannot  be  considered  conclusive  when  one  considers 
the  catalytic  effect  of  glass  upon  the  dehydrogenation  of 
alcohols  at  temperatures  even  below  those  used  in  this 
expe  riment . 


1.  J.C.S.  T ( 1902 ) 535  - Tfl903)  1075 


-3- 


OEgOH  — > ECHO  f-  H2 

The  only  conclusion  that  can  he  drawn  is  that  if  methyl 

alcohol  is  formed  its  decomposition  into  formaldehyde  at 

this  temperature  is  extremely  rapid. 

Proof  that  methyl  alcohol  is  an  intermediate  product 

in  the  oxidation  of  methane  is  given  hy  oxidizing  the 

methane  at  lower  temperatures  with  more  active  oxidizing  ag 
2 

agents.  Otto  showed  that  when  methane  was  oxidized  hy 
ozone  at  room  temperature , methyl  alcohol,  formaldehyde 
and  formic  acid  were  the  principal  products.  However  if 
the  oxidation  was  carried  out  above  100°0  only  formaldehye 
and  formic  acid  was  formed.  Evidently  the  reaction 
CH30H-^  HCHO  f H20 

is  greatly  accelerated  hy  a slight  increase  in  temperature . 
Lance  and  Elsworthy2  claim  the  production  of  methyl 
alcohol,  formaldehyde  and  formic  acid  from  methane  using 
hydrogen  peroxide  or  persulfuric  acid  as  an  oxidant  in 
the  presence  of  ferrous  sulfate  as  a catalyst. 

In  both  of  the  above  cases  the  active  oxidizing  agent 
is  probably  atomic  oxygen,  the  ferrous  salt  serving  to 
accelerate  the  decomposition  of  the  peroxides  in  the 
second  case. 

o3^o2*o 

n202  -^H2Of  0 

2.  Ann.  Ghim.  phys.  1898VII.13  77-144.  2.  B.£.7297  1916 


-4- 


E^SgOg  + Er.O  — > 2E2S04  + 0 

In  order  then  to  obtain  methyl  alcohol  from  methane 
the  process  would  have  to  be  carried  out  at  a low 
temperature.  Formaldehyde  may  be  obtained  at  much  higher 
temperatures  but  the  yield  decreases  with  an  increase 
in  temperature.  Thus  the  yield  obtained  by  Bone  and 
Wheeler  at  500°  C.  was  20$  while  Glock^bby  rapidely 
cooling  the  products  of  combustion  at  8()0oC  was  able  to 
obtain  only  traces  of  formaldehyde. 

It  would  seem  from  consideration  of  volume  and  heat 
changes  that  the  Le'Chateli&r  principle  could  be  applied 
to  this  reaction. 

CH4  -f-  1/2  0g— >CH30H  -+  42,900  Cal.  l/2  mole  decrease 

CH30H+  1/2  02— * ECE0+-  H20  +33,000  Cal.  l/2  mole  increase 

ECHO  + 1/2  02->C0+E20+-  20,000  Cal.  l/2  mole  increase 

ECHO  ■+  Og  — + C02+E20^1S7 ,000  Cal.  no  change. 

It  would  seem  that  an  increase  in  pressure  would  shift  the 
equilibrium  point  of  the  first  reaction  to  the  right, 
the  equilibrium  points  of  the  second  and  third  reactions 
to  the  left,  while  it  would  have  no  effect  upon  the  last 
one.  An  increase  in  temperature  would  favor  the  third 
reaction,  while  it  would  shift  the  equilibrium  point  of 
the  others  to  the  left. 

Eowever  very  little  importance  can  be  given  to  these 
considerations  as  the  equilibrium  point  is  never  reached. 


-5- 


Indeed  it  is  not  desirable  to  reach  the  equilibrium  point 
for  there  all  conditions  would  favor  the  decomposition  of 
any  methyl  alcohol  and  formaldehyde.  If  the  space  velocity 
of  the  gases  over  the  catalyst  is  not  high  the  dehydrogen- 
ation of  these  products  tends  to  occur.  The  problem  is  onfc 
that  involves  the  acceleration  of  the  first  two  reactions 
and  depressing  the  velocity  of  the  last  two  rather  than  one 
that  involves  equilibrium  points. 

In  choosing  a catalyst  for  this  reaction  there  are 
several  points  to  be  considered.  First:  the  catalyst  must 
be  able  to  furnish  oxygen  to  the  reaction  in  a more  active 
state  than  atmospheric  oxygen  so  that  the  reaction  may 
proceed  at  as  low  a temperature  as  possible.  Second:  the 
catalyst  must  not  accelerate  secondary  reactions  such  as 
the  dehydration  and  dehydrogenation  of  the  methyl  alcohol 
and  formaldehyde. 

The  first  condition  might  be  met  by  metals  that  have 
the  property  of  forming  more  than  one  oxide,  thus  permitting 
the  assumption  of  an  oscillating  oxide  as  an  oxygen  carrier. 

Ffl  g C — ^ i'1  e £ C _ t"  C 

2CuO  — 7 Cu  0 +-  0 2Cu  0 
Thus  a large  list  of  metals  having  more  than  one  oxide 
might  be  tried  as  fulfilling  this  condition  as  platinum, 
iron,  nickel,  cobalt,  tin,  copper,  manganese,  vanadium, 
chromium,  uranium,  etc.  if  it  were  not  for  secondary 
reactions . 


3.  DRP  107014. 


*• 


-6- 


All  of  these  metals  are  effective  catalysts  for  the 

following  reactions; 

CH  OK  HCHO  + Kp 
3 * 

ECHO  -V  CO  + Eg 
especially  at  elevated  temperatures. 

Even  in  the  case  of  copper  which  is  less  active  in 
this  respect  than  most  of  the  others  the  decomposition 
into  carbon  monoxide  and  hydrogen  is  practically  complete 
at  350°  at  low  space  velocities.  However  if  proper  space 
velocities  are  used  with  copper  as  a catalyst  methyl  ^ 

alcohol  can  be  oxidized  to  formaldehyde  giving  a yield  of 

4 

over  70%,  showing  that  so  far  as  the  secondary  reactions 
are  concerned  copper  could  he  used  as  a catalyst  in  the 
oxidation  of  methane  to  formaldehyde.  One  would  not  expect 
to  obtain  any  methyl  alcohol  with  such  a catalyst.  This 
secondary  reaction  would  prevent  the  use  of  iron,  cohalt, 

5 

nickel  and  the  platinum  metals  as  catalysts  in  this  reaction. 

The  above  conclusions  are  embodied  in  a number  of  p 
patents. 

Glock  in  1898  suggested  the  passage  of  methane  and 
air  over  granulated  copper  at  800°  0. 

Blackmore ' in  1904  states  than  methane  passed  over 
certain  oxides  yields  methyl  alcohol  at  128°0  and  form- 
aldehyde at  160°C.  The  yields  in  both  cases  were  placed  at 
90%.  The  oxides  used  were  CuO,  Fe^O^,  MnQ^  and  BaOg. 

4.  Hochstater  B.P.  464/1914.  5.  Eider  and  Taylor  p.  128 

6.  D.R.P.  107,014  7.  TT.S.P.  774,824.  8.  D.R.P.  214,155 

D.R.P.  286,731  1906 


-7- 


Another  German  patent  states  that  formaldehyde  is  formed 

if  methane  and  a large  excess  of  moist  air  is  passed  over 

metallic  copper  of  silver  or  "both.  The  formaldehyde  may  "be 

removed  and  the  mixture  passed  over  the  catalyst  repeatedly. i 

One  of  the  more  novel  catalytic  agents  proposed  was  tan 

a 9 

"bark.  The  Sanerstoff  and  Stickstoff  Ind.°  and  V.Tjnruh  claim 
that  the  oxidation  of  methane  "by  air  takes  place  at  30  - 50°  0. 
in  the  presence  of  s-nch  material.  It  is  probable  that  the 
aldehyde  itself  was  derived  from  the  tanbark.1^ 


i.  D.R.P.  286,731  Angeo  ’13 

8.  D.R.P.  214,155/1906 

9.  TT.S.P.  891,753/1907 

10.  Rideal  and  Taylor  131. 


_j5| 

* 


. 

* 

.... 
( e « * 

. 


-8- 


EXPERIMENTAI. 

The  Preparation  of  Methane. 

The  methane  used  in  this  work  was  prepared  by  the  soda- 
lime  fusion  of  sodinm  acetate. 

CHgCOOKa  f NaOH  — > OK A -h  Ma2C03 
Freshly  fused  sodium  acetate  was  heated  with  soda-lime  in  a 
pyrex  flask.  The  methane  obtained  by  this  process  was  impure 
being  contaminated  by  acetone,  some  -Hnsatr! rated  hydrocarbons, 
and  hydrogen.  The  acetone  and  unsjf^-nrated  hydrocarbons  were 
removed  by  passing  the  gas  slowly  first  through  acid  potassittn 
permanganate  and  then  through  concentrated  sulfuric  acid. 

The  purified  methane  contained  some  hydrogen  but  this  would 
have  no  effect  upon  the  experiment  as  it  was  oxidized  in  most 
cases  upon  the  first  passage  of  the  gas  over  the  catalyst. 

Method  of  Procedure. 

The  methane  stored  in  bottle  A was  passed  in  certain 
experiments  through  wash  bottle  0 filled  with  sulfuric  acid 
to  dry  the  gas,  in  other  experiments  through  a wash  bottle 
filled  with  water  maintained  at  a constant  temperature  so  as 
to  insure  certain  constant  concentrations  of  H20  in  the  gas. 

It  was  then  passed  through  the  catalyst  contained  in  an 
apparatus  electrically  heated.  The  apparatus  used  was  one 
described  by  Rideal  and  Taylor^-1  After  passing  through  the 
catalyst  it  was  passed  through  a flack  immerged  in  an  ice 
bath  to  condense  the  water  together  with  any  methyl  alcohol 
which  may  have  been  formed.  The  gas  was  then  passed  through 
11.  R.  and  T.  p.  72. 


-9- 


a wash  hottle  filled  with  water  to  remove  any  formaldehyde. 
The  gas  was  then  lejid  had  to  gas  hottle  B. 

The  gas  was  forced  through  the  apparatus  at  varying 
speeds,  the  most  usual  speed  being  about  20  liters  per  hour. 
When  the  gas  in  A was  completely  forced  out  into  B the 
positions  of  the  bottles  was  reversed. 

At  the  end  of  the  run  the  contents  of  E and  F were 
examined  for  formaldehyde  and  methyl  alcohol. 

Breparati on_  of  the  Catalyst. 

Copper  nitrate  was  precipitated  by  II  a OH  and  the 
copper  hydroxide  changed  into  CuO  by  boiling;  after  filtering 
the  oxide  was  dried  at  200°  and  then  washed  and  redried. 

In  some  experiments  CuO  was  precipitated  upon  asbestos  fibre 
as  a support. 

In  the  experiments  using  metallic  copper  some  of  this 
CuO  was  reduces  in  the  catalysis  vessel  with  hydrogen. 

In  certain  experiments  Copper-silver  couples  were 
used.  They  were  prepared  by  igniting  Cu.0  moistened  with 
AglTOg  solution  and  reducing  with  hydrogen. 

Hickel  oxide  was  prepared  by  igniting  a mixture  of 
nickel  nitrate  and  sugar.  The  oxide  was  obtained  in  a very 
porous  form.  In  some  of  the  experiments  this  nickel  was 
reduced  with  hydrogen. 

Iron  oxide  was  prepared  by  igniting  iron  filings. 


- 


i „•  • 


-10- 


Resnlts. 


I.  Mixtures  of  eq-nal  volumes  of  dry  methane  and  oxygen. 
Metallic  Copper  as  a catalyst. 


Temperature 

Effect  upon  Catalyst 

MeOE 

HCEO 

50°  C. 

ho  effect 

hone 

hone 

100° 

ii  it 

i i 

i t 

150° 

it  it 

1 1 

i i 

200° 

it  ii 

i i 

250° 

Slowly  oxidized 

i i 

i t 

300° 

Oxidized 

i i 

i i 

350° 

t i 

i i 

t i 

400° 

Passed  over 

Oxide  rednced 
metallic  On  heated  to 

t i 

reddness  no 

Trace . 
trace  o 

II.  One  -volume 

of  Methane  , 2 volumes 

of  Oxygen. 

On  as  catalyst. 

50°-200° 

ho  effect 

hone 

hone 

300° 

On  oxidized 

i i 

1 1 

350° 

it  ii 

i i 

i t 

400° 

ii  it 

t i 

i t 

Red  heat 

it  it 

t i 

T T 

III.  One  volume  of  Methane -1  volume 

of  air. 

50°  - 200° 

ho  effect 

i i 

i t 

300° 

ii  ii 

i t 

i i 

350° 

Cu  oxidized 

t i 

i i 

400° 

Oxide  red-need 

i i 

Trace 

t t 

Red  heat 


t t 


1 j 


I 


r 


-11- 


IV.  Equal  volumes  of  Lie  thane  and  Oxygen. 

On,  Ag  o on pie  as  catalyst. 

Same  results  as  with  On  alone. 

V.  hioOg  and  Fe^Og  as  catalysts. 

ho  redaction  of  catalyst  apparent  and  no  formaldehyde 
formed  up  400°  C. 

VI.  Methane  alone.  CuO  as  Catalyst. 


Temp.  Effect  on  Catalyst. 

Me  Oil 

HCHO 

50°-300°  C. 

ho  effect 

hone 

hone 

350° 

Slow  redaction 

i i 

i i 

400° 

Reduction  to  metal  ' * 

1 1 

:.  Methane  Air 

Steam. 

Cn  as  Catalyst 

• 

50°  - 200° 

ho  effect 

hone 

hone 

300° 

Cn  oxidized 

1 1 

1 1 

350° 

it  ii 

I ! 

1 1 

400° 

Oxide  reduced 

i i 

Trace 

-12- 


C0HC1TJSI0N. 

So  far  as  can  be  judged  by  the  experimental  results  it 
is  impossible  to  obtain  any  methyl  alcohol  from  the  oxidation 
of  methane  using  metals  or  metallic  oxides  as  catalysts.  The 
claims  of  Blackinore  of  yields  of  90$  methyl  alcohol  from  the 
oxidation  of  methane  appear  to  be  unfounded.  Eis  claims  of 
90$  yields  of  formaldehyde  also  seem  to  be  much  larger  than 
the  results  of  this  work  would  indicate. 

It  would  seem  that  the  metals  and  metallic  oxides  studied 
exert  about  the  same  catalytic  action  upon  the  combustion 
of  the  formaldehyde  as  upon  the  combustion  of  methane  to 
formaldehyde  for  no  greater  traces  of  formaldehyde  could  be 
found  than  in  the  suddenly  cooled  gases  from  a methane  flame. 


-13- 


BIBLIOGRAPHY. 

Bone  and  Wheeler-  J.C.S.  T (1902)  535 

J.S.C.  T (1903)  1075 

Otto  Ann.  Chim.  Phys.  1898.  VII-13  77  -144 

Rideal  and  Taylor  Catalysis  in  Theory  and  Practice. 

B.P.  7297/1916 
B.P.  464/1914 
D. R. P.  286,731/1913 
D.R.P.  107,014 
D.R. P.  214,155/1906 
TT.3.P.  774,824 
U.S.P.  891,753/1907 


